Re: [PATCH linux-next] media: i2c: st-mipid02: replace of_node_put() with __free

[R Sundar <prosunofficial@xxxxxxxxx>]

On 29/04/24 14:22, Benjamin Mugnier wrote:
> Hi,
>
> Thank you for your patch.
>
> On 4/27/24 11:56, R Sundar wrote:
> > Use the new cleanup magic to replace of_node_put() with
> > __free(device_node) marking to auto release and to simplify the error
> > paths.
> >
> > Suggested-by: Julia Lawall <julia.lawall@xxxxxxxx>
> > Signed-off-by: R Sundar <prosunofficial@xxxxxxxxx>
>
> I was not aware of this kind of auto release mechanism. Thanks for
> bringing that to my eyes.
>
> Now I looked in /drivers/media and couldn't find such structure. All
> drivers seem to follow the goto error_of_node_put style.
> As I'm unsure if we want to introduce such magic, could either Laurent
> or Sakari comment on this ?
>
> > ---
> >   drivers/media/i2c/st-mipid02.c | 37 +++++++++-------------------------
> >   1 file changed, 9 insertions(+), 28 deletions(-)
> >
> > diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
> > index f250640729ca..d42a306530f3 100644
> > --- a/drivers/media/i2c/st-mipid02.c
> > +++ b/drivers/media/i2c/st-mipid02.c
> > @@ -715,31 +715,28 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
> >   	struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
> >   	struct i2c_client *client = bridge->i2c_client;
> >   	struct v4l2_async_connection *asd;
> > -	struct device_node *ep_node;
> >   	int ret;
> >   
> >   	/* parse rx (endpoint 0) */
> > -	ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
> > -						0, 0);
> > +	struct device_node *ep_node __free(device_node) =
> > +		of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 0, 0);
> >   	if (!ep_node) {
> >   		dev_err(&client->dev, "unable to find port0 ep");
> > -		ret = -EINVAL;
> > -		goto error;
> > +		return -EINVAL;
> >   	}
> >   
> >   	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
> >   	if (ret) {
> >   		dev_err(&client->dev, "Could not parse v4l2 endpoint %d\n",
> >   			ret);
> > -		goto error_of_node_put;
> > +		return ret;
> >   	}
> >   
> >   	/* do some sanity checks */
> >   	if (ep.bus.mipi_csi2.num_data_lanes > 2) {
> >   		dev_err(&client->dev, "max supported data lanes is 2 / got %d",
> >   			ep.bus.mipi_csi2.num_data_lanes);
> > -		ret = -EINVAL;
> > -		goto error_of_node_put;
> > +		return -EINVAL;
> >   	}
> >   
> >   	/* register it for later use */
> > @@ -750,7 +747,6 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
> >   	asd = v4l2_async_nf_add_fwnode_remote(&bridge->notifier,
> >   					      of_fwnode_handle(ep_node),
> >   					      struct v4l2_async_connection);
> > -	of_node_put(ep_node);
> >   
> >   	if (IS_ERR(asd)) {
> >   		dev_err(&client->dev, "fail to register asd to notifier %ld",
> > @@ -764,46 +760,31 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
> >   		v4l2_async_nf_cleanup(&bridge->notifier);
> >   
> >   	return ret;
> > -
> > -error_of_node_put:
> > -	of_node_put(ep_node);
> > -error:
> > -
> > -	return ret;
> >   }
> >   
> >   static int mipid02_parse_tx_ep(struct mipid02_dev *bridge)
> >   {
> >   	struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_PARALLEL };
> >   	struct i2c_client *client = bridge->i2c_client;
> > -	struct device_node *ep_node;
> >   	int ret;
> >   
> >   	/* parse tx (endpoint 2) */
> > -	ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
> > -						2, 0);
> > +	struct device_node *ep_node =
> > +		of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 2, 0);
>
> Shouldn't there be a '__free' here too ?

my Bad.
Yes, It should come here also. Thanks!!
Will update the patch.

Thanks,
Sundar